Surgical table and method of operating the same

ABSTRACT

A surgical table includes a mechanism for causing movement of a tabletop of the table relative to a column of the table in a selected longitudinal or transverse direction of the tabletop, the mechanism including first and second drive elements movably mounted on one of the column and the tabletop and a traverse device mounted on the other of the column and the tabletop, wherein the tabletop is movable relative to the column between a predetermined traverse position, at which both of the first and second drive elements are engaged with the traverse device, and a first traverse position, at which the first drive element is engaged with the traverse device and the second drive element is disengaged from the traverse device. Also described is a system for helping a user dispose a tabletop of a table a predetermined position relative to a column of the table.

FIELD OF THE INVENTION

The present invention relates to surgical tables and to methods ofoperating surgical tables.

BACKGROUND

Surgical tables, or operating tables, comprising a base for standing ona floor, a column extending from the base, and a tabletop providing apatient support surface are well known.

In order for surgical tables to be versatile, it is necessary for thetabletop to be disposable in a variety of different configurations.WO2003/030802 discloses a surgical table with mechanisms for inclining atabletop of the table relative to a column of the table and relative tothe horizontal about both transverse and longitudinal axes of thetabletop, and a drive assembly for permitting a traverse movement of thetabletop relative to the column in back and forth longitudinaldirections of the tabletop.

Anthropometric data of the world's population is shifting over time.

SUMMARY OF THE INVENTION

There is a need for a surgical table with a more compact mechanism fordisposing a tabletop in a variety of different configurations.

There also is a need for a surgical table with a mechanism for disposinga tabletop in a greater variety of different configurations, in order toincrease the versatility of the surgical table for serving thepopulation as anthropometric data shifts over time.

Surgical tables may have a tabletop and a column that are movablerelative to each other between first and second relative positions via apredetermined relative position, such as a predetermined default or homeposition. Such a predetermined relative position may be, for example,the position at which a patient is most easily transferrable onto orfrom the table, the position at which the table is most stable, or theposition at which the table is best placed to enable a certain procedureto be performed on a patient supported by the table.

There is a need for a surgical table having an assistance mechanism forhelping medical staff using the surgical table to dispose a tabletop anda column of a surgical table at such a predetermined relative position.

A first aspect of the present invention provides a surgical tablecomprising: a base for standing on a floor; a column extending from thebase; a tabletop providing a patient support surface; and a tabletoptraverse drive mechanism coupling the tabletop to the column, whichtabletop traverse drive mechanism is for causing movement of thetabletop relative to the column in a selected longitudinal or transversedirection of the tabletop; wherein the tabletop traverse drive mechanismcomprises a driver, first and second drive elements that are drivable bythe driver, and a traverse device that is drivable by each of the firstand second drive elements, the first and second drive elements beingmovably mounted on one of the column and the tabletop and the traversedevice being mounted on the other of the column and the tabletop; andwherein the driver is operable to drive the first and second driveelements to drive the traverse device to cause movement of the tabletoprelative to the column between a predetermined traverse position, atwhich both of the first and second drive elements are engaged with thetraverse device, and a first traverse position, at which the first driveelement is engaged with the traverse device and the second drive elementis disengaged from the traverse device.

Optionally, the driver is operable to drive the first and second driveelements to drive the traverse device to cause movement of the tabletoprelative to the column to a second traverse position, at which thesecond drive element is engaged with the traverse device and the firstdrive element is disengaged from the traverse device.

Optionally, the first and second drive elements are movably mounted onthe column and the traverse device is mounted on the tabletop.

Optionally, the first and second drive elements are rotatably mounted onthe one of the column and the tabletop.

Optionally, the first and second drive elements are mounted for rotationabout respective first and second axes that are both perpendicular tothe longitudinal direction of the tabletop, or that are both parallel tothe longitudinal direction of the tabletop. Optionally, one or each ofthe first and second axes is perpendicular to a lateral direction of thetabletop, which lateral direction of the tabletop is perpendicular tothe longitudinal direction of the tabletop. Optionally, one or each ofthe first and second axes is parallel to a lateral direction of thetabletop, which lateral direction of the tabletop is perpendicular tothe longitudinal direction of the tabletop.

Optionally, the first and second drive elements are meshed with thetraverse device when the tabletop is at the predetermined traverseposition.

Optionally, the first and second drive elements are first and secondpinion gears.

Optionally, the traverse device is a rack.

Optionally, the traverse device is linear and aligned with thelongitudinal direction of the tabletop.

Optionally, the first and second drive elements are spaced apart in adirection that is parallel to the longitudinal direction of thetabletop.

Optionally, the driver comprises a motor connected to both the first andsecond drive elements for driving both the first and second driveelements.

Optionally, the surgical table comprises a controller for controllingoperation of the tabletop traverse drive mechanism. Optionally, thecontroller is configured to control the tabletop traverse drivemechanism to cause movement of the tabletop relative to the columnbetween the first and second traverse positions via the predeterminedtraverse position, and configured, when the tabletop is at thepredetermined traverse position relative to the column, to control thetabletop traverse drive mechanism to cause the movement of the tabletoprelative to the column to be paused for a predetermined period of time.

Optionally, the surgical table comprises a sensor for sensing, and fornotifying the controller of, a relative position of the tabletop and thecolumn. Optionally, the sensor is for sensing, and for notifying thecontroller of, when the tabletop is at the predetermined traverseposition relative to the column.

Optionally, the predetermined period of time is between 0.05 and 5seconds. Further optionally, the predetermined period of time is between0.1 and 3 seconds. Further optionally, the predetermined period of timeis between 0.25 and 2 seconds.

A second aspect of the present invention provides a surgical tablecomprising a base for standing on a floor; a column extending from thebase; a tabletop providing a patient support surface; a tabletoptraverse drive mechanism coupling the tabletop to the column, whichtabletop traverse drive mechanism is for causing movement of thetabletop relative to the column in a selected longitudinal or transversedirection of the tabletop; and a controller for controlling operation ofthe tabletop traverse drive mechanism; wherein the controller isconfigured to control the tabletop traverse drive mechanism to causemovement of the tabletop relative to the column between first and secondtraverse positions via a predetermined traverse position, andconfigured, when the tabletop is at the predetermined traverse positionrelative to the column, to control the tabletop traverse drive mechanismto cause the movement of the tabletop relative to the column to bepaused for a predetermined period of time.

Optionally, the tabletop traverse drive mechanism is for causingmovement of the tabletop relative to the column in a selectedlongitudinal direction of the tabletop.

Optionally, the surgical table comprises a sensor for sensing, and fornotifying the controller of, a relative position of the tabletop and thecolumn. Optionally, the sensor is for sensing, and for notifying thecontroller of, when the tabletop is at the predetermined traverseposition relative to the column.

Optionally, the predetermined period of time is between 0.05 and 5seconds. Further optionally, the predetermined period of time is between0.1 and 3 seconds. Further optionally, the predetermined period of timeis between 0.25 and 2 seconds.

A third aspect of the present invention provides a method of operating asurgical table having a base for standing on a floor; a column extendingfrom the base; a tabletop providing a patient support surface; atabletop traverse drive mechanism coupling the tabletop to the column,which tabletop traverse drive mechanism is for causing movement of thetabletop relative to the column in a selected longitudinal or transversedirection of the tabletop; and a controller for controlling operation ofthe tabletop traverse drive mechanism, the method comprising: thecontroller controlling the tabletop traverse drive mechanism to causemovement of the tabletop relative to the column between first and secondtraverse positions via a predetermined traverse position; and thecontroller controlling the tabletop traverse drive mechanism to causethe movement of the tabletop relative to the column to be paused for apredetermined period of time when the tabletop is at the predeterminedtraverse position relative to the column.

Optionally, the tabletop traverse drive mechanism is for causingrelative movement of the tabletop relative to the column in a selectedlongitudinal direction of the tabletop.

Optionally, the method comprises sensing a relative position of thetabletop and the column. Further optionally, the method comprisessensing when the tabletop is at the predetermined traverse positionrelative to the column.

Optionally, the predetermined period of time is between 0.05 and 5seconds. Further optionally, the predetermined period of time is between0.1 and 3 seconds. Further optionally, the predetermined period of timeis between 0.25 and 2 seconds.

A fourth aspect of the present invention provides a computer programproduct for causing a surgical table to perform the method of the thirdaspect of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

Preferred embodiments of the present invention will now be described byway of example only with reference to the accompanying drawings, inwhich:—

FIG. 1 is a schematic side view of a surgical table in accordance withan embodiment of the present invention;

FIG. 2A is a top plan view of a top portion of the column and the lowertorso section of the surgical table of FIG. 1, with the mattress of thelower torso section removed and with the lower torso section at apredetermined traverse position relative to the column;

FIG. 2B is a side view of the components shown in FIG. 2A;

FIG. 2C is a bottom view of the components shown in FIG. 2A;

FIG. 3A is a top plan view of a top portion of the column and the lowertorso section of the surgical table of FIG. 1, with the mattress of thelower torso section removed and with the lower torso section at a firsttraverse position relative to the column;

FIG. 3B is a side view of the components shown in FIG. 3A;

FIG. 3C is a bottom view of the components shown in FIG. 3A;

FIG. 4A is a top plan view of a top portion of the column and the lowertorso section of the surgical table of FIG. 1, with the mattress of thelower torso section removed and with the lower torso section at a secondtraverse position relative to the column;

FIG. 4B is a side view of the components shown in FIG. 4A; and

FIG. 4C is a bottom view of the components shown in FIG. 4A.

DETAILED DESCRIPTION

Referring to FIG. 1, a surgical table, designated generally as 2,includes a base 4, which stands on a floor 6, a column 8 of adjustableheight extending from the base 4 and a tabletop 10 providing a patientsupport surface 12. In a variation to this embodiment, the column 8 isnot of adjustable height. The base 4 may include wheels for moving thetable 2 along the floor 6.

As depicted in FIG. 1, the tabletop 10 is divided into five sections,namely a head section 14, an upper torso section 16, a lower torsosection 18 and a pair of laterally adjacent leg sections 20, 20, ofwhich only one is shown in FIG. 1. Each of the sections of the tabletop10 provides a portion of the patient support surface 12, and each of thesections has a respective separate mattress 22, 24, 26, 28, 28.

The lower torso section 18 is coupled to the column 8. A lower end 35 ofthe upper torso section 16 is detachably mounted on an upper end 41 ofthe lower torso section 18 by means of transversely adjacent first andsecond pivot joints 30, 32, which define a transverse axis about whichthe upper torso section 16 can be displaced relative to the lower torsosection 18.

Each of the leg sections 20 is detachably mounted on a lower end 42 ofthe lower torso section 18 by a respective one of transversely adjacentthird and fourth pivot joints 44, 46, of which only one is visible inFIG. 1, for displacement relative to the lower torso section 18 about atransverse axis defined by the respective one of third and fourth pivotjoints 44, 46.

A lower end 34 of the head section 14 is detachably mounted on an upperend 36 of the upper torso section 16 by means of a fifth pivot joint 38defining a transverse axis about which the head section 14 can bedisplaced relative to the upper torso section 16. The angle ofinclination of the head section 14 is controlled manually by means of apair of conventional adjustable struts 40, only one of which is shown inFIG. 1, secured to and extending between the underside of the headsection 14 and the upper torso section 16, one on each side of thetabletop 10. The struts 40 may be hydraulic or electric actuators orlockable gas springs.

The provision of the five pivot joints 30, 32, 38, 44, 46 permits thefive sections 14, 16, 18, 20, 20 selectively to be inclined relative toadjacent sections 14, 16, 18, 20, 20 thereby to dispose the tabletop 10in a selected configuration. Moreover, that the head section 14 isdetachable from the upper torso section 16, and each of the upper torsosection 16 and the leg sections 20, 20 is detachable from the lowertorso section 18 means that the table 2 may be made compact for storage.

Although not expressly shown in the Figures, the surgical table 2 ofthis embodiment also includes a mechanism for inclining the wholetabletop 10 relative to the column 8 and relative to the horizontalabout transverse and longitudinal axes of the tabletop 10. Inclinationabout the transverse axis of the tabletop 10 is referred to in the artas “trending”, while inclination about the longitudinal axis of thetabletop 10 is referred to as “tilting”. Compound movements also arepossible, in which the tabletop 10 is inclined about both the transverseand longitudinal axes of the tabletop 10 at the same time.

As used herein, the longitudinal axis of the tabletop is the major axisof the tabletop and the transverse axis of the tabletop is theorthogonal minor axis of the tabletop. The longitudinal direction of thetabletop is parallel to the major axis and the transverse direction ofthe tabletop is parallel to the minor axis. That is, the transversedirection of the tabletop is perpendicular to, or orthogonal to, thelongitudinal direction of tabletop.

In variations to the illustrated embodiment, the tabletop 10 may bedivided into a different number and/or configuration of sections tothose shown in the Figures, or may not be divided into multiple sectionsat all. In such variations, the tabletop 10 may not include any sectionsthat are relatively inclinable to each other by pivoting about atransverse axis defined by a pivot joint. In some such variations, thetable 2 still includes a mechanism for inclining the whole tabletop 10relative to the column 8 and/or relative to the horizontal abouttransverse and/or longitudinal axes of the tabletop 10. In othervariations, no such mechanism is provided, and the whole tabletop 10 isnot inclinable relative to the column 8 and relative to the horizontal.

The surgical table 2 further is provided with a tabletop traverse drivemechanism 100 mounted between the underside of the tabletop 10 and thetop of the column 8 for causing movement of the tabletop 10 relative tothe column 8 in a selected longitudinal direction of the tabletop 10.The tabletop 10 is coupled to the column 8 via the tabletop traversedrive mechanism 100, with the tabletop traverse drive mechanism 100permitting relative movement of the tabletop 10 and the column 8.Operation of the tabletop traverse drive mechanism 100 is controlled bya controller (not shown) of the surgical table 2. The controllercontrols the tabletop traverse drive mechanism 100 in dependence on oneor more instructions received at the controller from a user interface(not shown) of the operating table.

Referring to FIGS. 2A to 2C, the tabletop traverse drive mechanism 100comprises a driver in the form of a motor (not shown), a drive gear 102for being driven by the motor, first and second drive elements in theform of first and second pinion gears 104, 106 that are meshed with thedrive gear 102 so as to be drivable by the motor via the drive gear 102,and a traverse device in the form of a rack 108 that is meshed with thefirst and second pinion gears 104, 106 so as to be drivable by each ofthe first and second pinion gears 104, 106. The motor may be anelectrically-powered motor. Any suitable mechanism for causing the drivegear 102 to be driven by the motor may be provided. For example, thedrive gear 102 may be fixed to a spindle of the motor, so that rotationof the spindle about an axis causes rotation of the drive gear 102 aboutthe same axis. Alternatively, the drive gear 102 may be indirectlyconnected to a spindle of the motor, such as by one or more furthergears. For example, a primary gear (not shown), such as a worm gear, maybe fixed to the spindle of the motor, which primary gear is meshed withthe drive gear 102 so that rotation of the spindle causes rotation ofthe primary gear which, in turn, causes rotation of the drive gear 102.

In the illustrated embodiment, the motor is mounted on the column 8beneath a cover 40 covering a top of the column 8, the drive gear 102and first and second pinion gears 104, 106 are rotatably mounted on thecolumn 8 beneath the cover 40, and the rack 108 is mounted on an innerside of a first frame member 18 a of a pair of lateral frame members 18a, 18 b of the lower torso section 18 of the tabletop 10. In variationsto this embodiment, the motor is mounted on the tabletop 10, the drivegear 102 and first and second pinion gears 104, 106 are rotatablymounted on the tabletop 10, and the rack 108 is mounted on the column 8.

The first and second pinion gears 104, 106 are mounted on the column 8for rotation about respective first and second axes A1, A2, which axesA1, A2 are both perpendicular to the longitudinal direction of thetabletop 10. Moreover, the axes A1, A2 are both perpendicular to alateral direction of the tabletop 10, which lateral direction of thetabletop 10 is perpendicular to the longitudinal direction of thetabletop 10. This arrangement minimises the vertical height of the firstand second pinion gears 104, 106, which permits the patient supportsurface 12 to be low. The first and second pinion gears 104, 106, andtheir respective first and second axes A1, A2, are spaced apart in adirection that is parallel to the longitudinal direction of the tabletop10, and the rack 108 is linear and aligned with the longitudinaldirection of the tabletop 10. That is, the rack 108 has finite lengthand two opposed ends 108 a, 108 b that are spaced apart in a directionthat is parallel to the longitudinal direction of the tabletop 10.

In variations to the illustrated embodiment, one or each of the axes A1,A2 is parallel to the longitudinal direction of the tabletop 10 orparallel to the lateral direction of the tabletop 10. In someembodiments, one of the axes A1, A2 is perpendicular to the lateraldirection of the tabletop 10, while the other of the axes A1, A2 isparallel to the lateral direction of the tabletop 10.

The tabletop traverse drive mechanism 100 further comprises first andsecond telescopic stabiliser arms 120, 130 slidably connected betweenrespective lateral sides of the column 8 and respective ones of the pairof lateral frame members 18 a, 18 b of the lower torso section 18 of thetabletop 10. More particularly, a first track 122 of the firsttelescopic stabiliser arm 120 is slidably engaged with a track 8 a on afirst lateral side of the column 8, and a second track 124 of the firsttelescopic stabiliser arm 120 is slidably engaged with a track 18 c onthe first frame member 18 a of the lower torso section 18 of thetabletop 10. Similarly, a first track 132 of the second telescopicstabiliser arm 130 is slidably engaged with a track 8 b on a secondlateral side of the column 8, and a second track 134 of the secondtelescopic stabiliser arm 130 is slidably engaged with a track 18 d onthe second frame member 18 b of the upper torso section 16 of thetabletop 10.

Although not expressly shown in the Figures, each of a first pair ofcooperable stop features is provided on a respective one of the firsttrack 122 of the first telescopic stabiliser arm 120 and the track 8 aon the first lateral side of the column 8, to limit the possible rangeof movement of the first track 122 relative to the track 8 a back andforth in the longitudinal direction of the tabletop 10. Each of a secondpair of cooperable stop features is provided on a respective one of thesecond track 124 of the first telescopic stabiliser arm 120 and thetrack 18 c on the first frame member 18 a of the lower torso section 18of the tabletop 10, to limit the possible range of movement of thesecond track 124 relative to the track 18 c back and forth in thelongitudinal direction of the tabletop 10. Each of a third pair ofcooperable stop features is provided on a respective one of the firsttrack 132 of the second telescopic stabiliser arm 130 and the track 8 bon the second lateral side of the column 8, to limit the possible rangeof movement of the first track 132 relative to the track 8 b back andforth in the longitudinal direction of the tabletop 10. Each of a fourthpair of cooperable stop features is provided on a respective one of thesecond track 134 of the second telescopic stabiliser arm 130 and thetrack 18 d on the second frame member 18 b of the lower torso section 18of the tabletop 10, to limit the possible range of movement of thesecond track 134 relative to the track 18 d back and forth in thelongitudinal direction of the tabletop 10. The first to fourth pairs ofcooperable stop features together limit the possible range of movementof the tabletop 10 relative to the column 8 back and forth in thelongitudinal direction of the tabletop 10.

Operation of the tabletop traverse drive mechanism 100 will now bedescribed.

In FIGS. 2A to 2C, the tabletop 10 is shown at a predetermined traverseposition relative to the column 8 with both of the first and secondpinion gears 104, 106 meshed with the rack 108. When a user wishes totraverse the tabletop 10 relative to the column 8, they operate the userinterface to cause the user interface to send an instruction to thecontroller, which causes the controller to cause the motor to beenergised, to operate in either a forward or reverse rotational mode independence on a content of the instruction from the user interface. Theenergisation of the motor causes the drive gear 102 to be rotated by themotor, thereby causing the first and second pinion gears 104, 106 to belongitudinally driven along the rack 108. Accordingly, the rack 108,which is rigidly attached to the lower torso section 18 of the tabletop10, is longitudinally driven back or forth relative to the column 8 towhich the first and second pinion gears 104, 106, the drive gear 102 andalso the motor, are mounted. This traverses the tabletop 10 back andforth relative to the column 8.

The controller is operable, via the user interface, to cause the motorto drive the first and second pinion gears 104, 106 to drive the rack108, in order to cause movement (in the direction of arrow A in FIG. 3C)of the tabletop 10 relative to the column 8 between the predeterminedtraverse position, illustrated in FIGS. 2A to 2C, and a first traverseposition, illustrated in FIGS. 3A to 3C. During movement of the tabletop10 relative to the column 8 from the predetermined traverse positiontowards the first traverse position, the first and second pinion gears104, 106 are driven along the rack 108. Before the tabletop 10 reachesthe first traverse position, the second pinion gear 106 is driven offthe second end 108 b of the rack 108. However, the first pinion gear 104remains meshed with the rack 108, so that the rack 108 is drivable bythe first pinion gear 104 and continued driving of the first pinion gear104 by the motor continues to move the tabletop 10 relative to thecolumn 8 until the tabletop 10 reaches the first traverse positionrelative to the column 8. When the tabletop 10 is at the first traverseposition relative to the column 8, the first pinion gear 104 still isengaged with the rack 108 but the second pinion gear 106 is disengagedfrom the rack 108. That is, there is no contact between the secondpinion gear 106 and the rack 108.

Similarly, the controller also is operable, via the user interface, tocause the motor to drive the first and second pinion gears 104, 106 todrive the rack 108, in order to cause movement (in the direction ofarrow B in FIG. 4C) of the tabletop 10 relative to the column 8 betweenthe predetermined traverse position, illustrated in FIGS. 2A to 2C, anda second traverse position, illustrated in FIGS. 4A to 4C. Duringmovement of the tabletop 10 relative to the column 8 from thepredetermined traverse position towards the second traverse position,the first and second pinion gears 104, 106 are driven along the rack108. Before the tabletop 10 reaches the second traverse position, thefirst pinion gear 104 is driven off the first end 108 a of the rack 108.However, the second pinion gear 106 remains meshed with the rack 108, sothat the rack 108 is drivable by the second pinion gear 106 andcontinued driving of the second pinion gear 106 by the motor continuesto move the tabletop 10 relative to the column 8 until the tabletop 10reaches the second traverse position relative to the column 8. When thetabletop 10 is at the second traverse position relative to the column 8,the second pinion gear 106 still is engaged with the rack 108 but thefirst pinion gear 104 is disengaged from the rack 108. That is, there isno contact between the first pinion gear 104 and the rack 108.

It will thus be appreciated that, through the provision of the tabletoptraverse drive mechanism, the tabletop is movable relative to the columnin the longitudinal direction of the tabletop over a distance that isgreater than the length of the traverse device (the rack 108, in theillustrated non-limiting example embodiment) in the longitudinaldirection of the tabletop. The distance is not limited to the length ofthe traverse device (the rack 108, in the illustrated non-limitingexample embodiment). Thus, there is provided a compact mechanism fordisposing a tabletop over a broader range of positions relative to thecolumn, which increases the versatility of the surgical table.

Moreover, in embodiments of the invention (such as the illustratedembodiment) in which the surgical table includes a mechanism forinclining the tabletop relative to the horizontal about a transverseaxis of the tabletop, due to the provision of the tabletop traversedrive mechanism there is provided a compact mechanism for inclining thetabletop at a steep angle relative to the horizontal when the tabletopis positioned at or near to one or other of its longitudinal limitsrelative to the column. Accordingly, there is provided a compactmechanism for disposing a tabletop in a still greater variety ofdifferent configurations, in order to increase the versatility of thesurgical table.

In the illustrated embodiment, the driver of the tabletop traverse drivemechanism 100 comprises a single motor connected to both the first andsecond pinion gears 104, 106 for driving both the first and secondpinion gears 104, 106. The use of a single motor minimises complexity ofthe tabletop traverse drive mechanism and complexity of control of thetabletop traverse drive mechanism. In variations to this embodiment, thedriver may instead comprise a first motor connected to the first piniongear 104 for driving the first pinion gear 104, and a second motorconnected to the second pinion gear 106 for driving the second piniongear 106.

In the illustrated embodiment, the first and second drive elements areable to mesh with the traverse device. Such meshing reduces oreliminates slipping between the drive elements and the traverse device,which results in smooth and steady traversing of the tabletop, reducedwear of the tabletop traverse drive mechanism, and the ability toaccurately position the tabletop relative to the column. Each of thefirst and second drive elements is made from hardened steel and,preferably, has surfaces having a low coefficient of friction. In avariation to this embodiment, the first and second drive elements do notmesh with the traverse device. For example, the first and second driveelements may comprise first and second wheels with smoothcircumferential surfaces, and the traverse device may comprise a smoothplate along which the first and second wheels are driven. In suchembodiments, preferably one or both of the surface of the plate and thecircumferential surfaces of the first and second wheels have a highcoefficient of friction (e.g. through being made of rubber or anelastomer), to reduce or eliminate slipping between the wheels and theplate.

As discussed above, the tabletop 10 is traversable in a longitudinaldirection relative to the column 8. The table 2 of the illustratedembodiment includes an assistance mechanism for helping medical staffusing the table 2 to move the tabletop 10 relative to the column 8 in aselected longitudinal direction of the tabletop 10 to dispose thetabletop 10 and the column 8 at a predetermined relative position, suchas a predetermined default or home position.

In dependence on movement instruction(s) received at the controller fromthe user interface of the surgical table 2, the controller is configuredto control the tabletop traverse drive mechanism 100 to cause movementof the tabletop 10 relative to the column 8 between the first and secondpositions via the predetermined traverse position. When the tabletop 10is at the predetermined traverse position relative to the column 8, thecontroller controls the tabletop traverse drive mechanism 100 to causethe movement of the tabletop 10 relative to the column 8 to be pausedfor a predetermined period of time. In this embodiment, thepredetermined period of time is 2 seconds. However, in variations tothis embodiment, the predetermined period of time may be any timebetween 0.05 and 5 seconds, more preferably between 0.1 and 3 seconds,more preferably between 0.25 and 2 seconds, and most preferably between1 and 2 seconds. The controller is configured such that, if after elapseof the predetermined period of time the controller still is receivingfrom the user interface the movement instruction(s) to control thetabletop traverse drive mechanism 100 to cause the movement of thetabletop 10 relative to the column 8, then the controller controls thetabletop traverse drive mechanism 100 to cause the movement of thetabletop 10 relative to the column 8 to be resumed. The controller alsois configured such that, if after elapse of the predetermined period oftime the controller no longer is receiving from the user interface themovement instruction(s) to control the tabletop traverse drive mechanism100 to cause the movement of the tabletop 10 relative to the column 8,then the controller controls the tabletop traverse drive mechanism 100to cause the movement of the tabletop 10 relative to the column 8 not tobe resumed.

In this embodiment, the table includes a sensor (not shown)communicatively connected to the controller. The sensor comprises arotary encoder (not shown) fitted to the spindle of the motor andconfigured to output to the controller an indication of the currentposition of the spindle. Using the output of the rotary encoder, thecontroller keeps track of the current position of the spindle and, thus,is able to determine a current position of the tabletop 10 relative tothe column 8. The controller determines when the tabletop 10 is at thepredetermined traverse position relative to the column 8 using theoutput of the rotary sensor. The controller may determine when thetabletop 10 is at the predetermined traverse position relative to thecolumn 8 based on the number of detected rotations of the motor of thetabletop traverse drive mechanism 100 since the tabletop 10 began movingfrom one or other of the first and second traverse positions.

The sensor may also or alternatively comprise a rotary potentiometerconnected by a drive wheel to one of the drive elements 104, 106 andconfigured to output to the controller an indication of the currentposition of the drive element 104, 106. Using the output of the rotarypotentiometer, the controller keeps track of the current position of thedrive element 104, 106 and, thus, is able to determine a currentposition of the tabletop 10 relative to the column 8. Additionally oralternatively, a cable potentiometer may be used.

In variations to this embodiment, the sensor may comprise a micro switchmounted at the top of the column 8, and a portion of the tabletop 10 maybe configured to actuate the micro switch when the portion of thetabletop 10 passes the micro switch. The micro switch and the portion ofthe tabletop 10 are relatively disposed so that the portion of thetabletop 10 actuates the micro switch when the tabletop 10 is at thepredetermined traverse position relative to the column 8. In stillfurther variations, the sensor could take forms other than a microswitch and/or could comprise components located at different places onthe table.

In variations to this embodiment, the controller may determine when thetabletop 10 is at the predetermined traverse position relative to thecolumn 8 based on time elapsed since the tabletop 10 began moving fromone or other of the first and second traverse positions at a knownspeed. Other mechanisms for determining when the tabletop 10 is at thepredetermined traverse position relative to the column 8 also areusable.

It will thus be appreciated that, through the provision of theassistance mechanism, users of the surgical table are alerted as to whenthe tabletop is at the predetermined traverse position relative to thecolumn, and are given the predetermined period of time in which to causethe user interface to stop sending the movement instruction(s) to thecontroller. Thus, there is provided a mechanism for helping users of thesurgical table to dispose the tabletop of the surgical table at thepredetermined traverse position relative to the column.

The controller may be connected to memory storing instructions forcausing the controller to carry out one of the inventive methods of thepresent invention. Such memory may be considered to be an example of acomputer program product for causing an apparatus, such as thecontroller, to perform one of the inventive methods of the presentinvention.

Various modifications can be made to the above-described embodimentswithout departing from the scope of the present invention, which isdefined by the claims.

For example, in variations to the illustrated embodiment, in addition toor instead of the surgical table being provided with the tabletoptraverse drive mechanism for causing movement of the tabletop relativeto the column in a selected longitudinal direction of the tabletop, thesurgical table is provided with a tabletop traverse drive mechanismmounted between the underside of the tabletop and the top of the columnfor causing movement of the tabletop relative to the column in aselected transverse direction of the tabletop. Such an additional oralternative, respectively, tabletop traverse drive mechanism may haveany or all of the features and operation of the illustrated tabletoptraverse drive mechanism, but in order to permit movement of thetabletop relative to the column in a selected transverse direction ofthe tabletop rather than in a selected longitudinal direction of thetabletop. Through the provision of such an additional or alternative,respectively, tabletop traverse drive mechanism, the tabletop is movablerelative to the column in the transverse direction of the tabletop overa distance that is greater than the length of the traverse device (whichmay be a rack, similar to the rack 108) in the transverse direction ofthe tabletop. The distance is not limited to the length of the traversedevice. Thus, there is provided a compact mechanism for transverselypositioning the tabletop e.g. within an imaging device in order to imagea patient on the tabletop.

Moreover, in such variations to the illustrated embodiment, the surgicaltable may include an assistance mechanism for helping medical staffusing the table to move the tabletop relative to the column in aselected transverse direction of the tabletop to dispose the tabletopand the column at a predetermined relative position, such as apredetermined default or home position.

In variations to the above-described embodiments, the surgical table mayhave none, or only either one, of the above-described assistancemechanisms.

1. A surgical table comprising: a base for standing on a floor; a columnextending from the base; a tabletop providing a patient support surface;a tabletop traverse drive mechanism coupling the tabletop to the column,which tabletop traverse drive mechanism is for causing movement of thetabletop relative to the column in a selected longitudinal or transversedirection of the tabletop; and a controller for controlling operation ofthe tabletop traverse drive mechanism; wherein the controller isconfigured to control the tabletop traverse drive mechanism to causemovement of the tabletop relative to the column between first and secondtraverse positions via a predetermined traverse position, andconfigured, when the tabletop is at the predetermined traverse positionrelative to the column, to control the tabletop traverse drive mechanismto cause the movement of the tabletop relative to the column to bepaused for a predetermined period of time.
 2. A surgical table accordingto claim 1, wherein the tabletop traverse drive mechanism is for causingmovement of the tabletop relative to the column in a selectedlongitudinal direction of the tabletop.
 3. A surgical table according toclaim 1, comprising a sensor for sensing, and for notifying thecontroller of, a relative position of the tabletop and the column.
 4. Asurgical table according to claim 3, wherein the sensor is for sensing,and for notifying the controller of, when the tabletop is at thepredetermined traverse position relative to the column.
 5. A surgicaltable according to claim 1, wherein the predetermined period of time isbetween 0.05 and 5 seconds.
 6. A surgical table according to claim 5,wherein the predetermined period of time is between 0.1 and 3 seconds.7. A surgical table according to claim 6, wherein the predeterminedperiod of time is between 0.25 and 2 seconds.
 8. A method of operating asurgical table having a base for standing on a floor; a column extendingfrom the base; a tabletop providing a patient support surface; atabletop traverse drive mechanism coupling the tabletop to the column,which tabletop traverse drive mechanism is for causing movement of thetabletop relative to the column in a selected longitudinal or transversedirection of the tabletop; and a controller for controlling operation ofthe tabletop traverse drive mechanism, the method comprising: thecontroller controlling the tabletop traverse drive mechanism to causemovement of the tabletop relative to the column between first and secondtraverse positions via a predetermined traverse position; and thecontroller controlling the tabletop traverse drive mechanism to causethe movement of the tabletop relative to the column to be paused for apredetermined period of time when the tabletop is at the predeterminedtraverse position relative to the column.
 9. A method according to claim8, wherein the tabletop traverse drive mechanism is for causing relativemovement of the tabletop relative to the column in a selectedlongitudinal direction of the tabletop.
 10. A method according to claim8, comprising sensing a relative position of the tabletop and thecolumn.
 11. A method according to claim 10, comprising sensing when thetabletop is at the predetermined traverse position relative to thecolumn.
 12. A method according to claim 8, wherein the predeterminedperiod of time is between 0.05 and 5 seconds.
 13. A method according toclaim 12, wherein the predetermined period of time is between 0.1 and 3seconds.
 14. A method according to claim 13, wherein the predeterminedperiod of time is between 0.25 and 2 seconds.
 15. A computer programproduct for causing a surgical table to perform the method of claim 8.16. A surgical table according to claim 2, comprising a sensor forsensing, and for notifying the controller of, a relative position of thetabletop and the column.